Rotary pulp screen



Sept 13, 19.32@ y `T. OCQNNOR l 1,877,030

ROTARY PULP S CREEN vFiled April l5. 1930 Patented Sept. 13, 1932 www ,STATES THOMAS CONNOR, OF PHILADELPHIA, PENNSYLVANIA ROTARY PULP s'ci'zlEEN Application filedA April 16,

My invention relates to screens ofthe rtary type'for the treatment of pulp, and it is adapted for the treatment either of what is known as ground wood 'pulp or chemical pulp. The screen as illustrated is of a character such that it is primarily adapted for use in the treatment or handling of pulp just previous to its delivery to a aper making machine. ",Although l as in icated the screen as illustrated is adapted for use at the point stated in the process vof treating the pulp employed inthe manufacture of paper yetit should be understood thatfitlmay be adapted for use atan earlier stage' in the preparation of the pulp.

The type of screen as illustrated and constituting one embodiment yof my invention is used for the most part in-connection witha paper making machine where a screen is re- 29 quired for the breaking up of libre bundles and to keep' foreign material lfrom reaching. the paper making machine. Screens employed at this point 'in the manufacture of paper are used for line screening work. 5 Their purpose or object broadly is to agitate the pulp, which should be thin, for the purpose of maintaining the finely comminuted fibres thoroughly distributed throughout the water by which they are conveyed through 39 the pulp handling apparatus to the pap-er making machine.

The general object of my invention is to provide a rotary screen of the character hereinbefore indicated having novel means for elcctingin a highly efficient manner the agitation o'l the pulp mass and for breaking up the libre bundles or clots and also for breaking up into small particles all foreign material which may have reached the said screen. By thus breaking up and disintegrating lumps of any kind which may reach the screen I am enabled to prevent the same from reaching the paper making machine and thereby to prevent the formation of bad spots in the paper which may be produced upon such machine.

It may be noted that when the pulp has reached a screen of this character, which is employed for a final treatmentor at least one of the linal treatments of the pulp before it is run intofthe paper makingmacliine,`the hard lumps lor particles? haye alreadybeen' removed therefrom. As valready indicated, the stock should be thin so that the finely comminuted libres'ljoflpthe'fpull 'mayb'thoi 55 oughly and eyenly'distribute therethrough. It also is an 'object'ofimj iliieiition tdp'rol: vide a i'otziuyl screen having means jforA iect ing a "preingorrushin "actionfand also simultaneously to' Q caiisef af forward 60 movementf ifth'est'ck through the screen: i lA further object of theinvention .is, to pro'- videy men'sfnefebi 'venons-,afar sind:

haviagben eeeuppn-byithfaigiitating' means mayreturn 'to position to be 55 again. tasted: iipnlby "fthe [,Siifeeitating.

It also .iS a'e'biectiof myinvegnon' te pro'.- vide a screen adaptedl for fine screening work comprising an-estetorhving statief 7 and man@rasieren.stationary parts constituting a"butnuui'tsv the operating surfaces of which are locatedin planes which occupy positions in non-parallel relation to the planes of the opposite v'sides of agitating blad es which constitute part'sff themovable member of the agitator, except when said agitating blades voccupy positions midway between adjoining abutments.

Other obj ects and advantages of my invenftion will be pointed out in the detailed description thereof which follows or will be apparent therefrom.

- In order that theinvention may be read? ily understood and its practical advantages fully appreciated reference 'should be had to the accompanying drawing wherein I have illustrated a structure in a'form which atl present-is preferred 4by me 'which embodies the invention'. However,'itfwill be -understood that the invention may -be embodied in other forms of construction than th at shown and that changes in the `details of con-struction may be made' within the s'cope of the claims without departing from the invention or the principle thereof.

In the drawing:

Fig. l is a view in transverse section of a screen Structure embodying my invention, the 100 said view being taken in the plane of the line 1--1 of Fig. 2;

Fig. 2 is a longitudinal section of such screen taken in the plane of the line 2--2 of Fig. 3 is a sectlonal view of a fragmentary portion of the structure taken on theangular line 3-'3 of Figi 1:,.the` pur joscofyfhicli'is'to show more clearly certain etails of construcf m tion; and

part of the troughe portion or tank of the structure constituting the stationary-part'- of the structure shown in Figs. 1 and 2.

In the drawing I have shown" t 1a base' having upright posts 2 and 3 thereon. Upon upperends of theposts 2 a stationary tank or trough member 4-is mounted theupper, Jde/of whi-n' is. openfras shown... The saidi trough-,like member isl provided u n.1tsmnerside with a plurality ofupwar .y tapered or .wedge-shaped projections 5 .which extend leligthwisethreoi -Thesaproiectene met a lengthr equal to.the;.inner side. of, maur es; body '.poitio'nof. the or trough.j ,4. Jhe

Opposite. eds 9i the tsoughareprpvef `alf-.11 outwardly; extending projections f5 .the .upper edges ofthe: otwhichv arefprovided with bearhs's'--witlnrwhch are iounnaldfthe OP: aus positefcnds of `al shaft 8. uponwhi'ch are. mortlskl'etohwheel`9.l1eYns-Qufier:rmS which't' in the opposite ends of ahll'w screening '-lhhisl drum. is provided in-l'mlown manner with extremely narrow nur slotsY 13' ofconsiderable length asindicatedin Fig. I of thefdrawing. ,Tli'eseslots inthe con? struction shown extend'around the' drum or concontrically with respect to the: axis ofi-.the shaft 8.l lhe-drurnisjrotatably driven by mean'sof power applied through a driving belt 15 to a wheel 16 mounted upon the shaft 8. The pulp or stock to be screened is delivered to the vtrough or tank'4 through a port 2O provided, in the 'construction as illustrated,l in the bottom thereof. The joints-between the opposite ends of the screen 12 andthe opposite end walls ofthe trough or tank are closed by-known means as indicated at 21 so that the stock which enters the' trough. or' tank throughA the port 20" must enter the drum through the screening perforations 13 provided therein.

As previously stated, the opposite sides of the projections 5 are tapered and it may be noted that the planes' of the sides are not located in planes4 which are radial with respect to: the 'axis of the rotary drum 12. The purpose of this arrangement of? roiatinmghip 0f the pjlanes of the opposite surfaces of the pro- "U" jections'v will be referred to and explained hereina'litelr.'

For the purpose of agitating 'thestock within the tank or trough '4 'have provided agitating bla-des or panels which consist of plates: 22tof lengths substantially equal to at intervals to the circular bars 24 which are '4;

located upon the inner side of the trough or tank 4in spaced relation thereto. as shown. Thesebars24 extend through notch'esor slots 25 provided in adjoining relation to the opposit'e`e'nds of the upwardly tapered projec- Fig. 4 Ais a view in. tolp plano'flthe stationary "tions 5; Gurved bars? 26f`sanilar to the bars 24 are located outside of the trough or tank near the opposite ends thereof.l as best shown in,l;ig. 2 ,of the drawing. The bars 2G 'are spaced from'the' said trough or tank as indicated at 27. Thel opposite ,upper ends o f thebars of' each. couple of -bazrs 24 and 26 are .connected together by means of inverted Ufshape members 30.1 The couplesof bar-s' 24 Vand J26fareconnected togethei; 'by means1 of plates -BfLwliicli ailiezmounted upon thefupper'end's. of saidibarsfand :which ex; tend'l frthwiseofwtheistructureJbetween the; two coup es as' shown' dashlines 2 :of the drawing. fOne 'of .the Iplates '31 isprovided; at its opposite; ends with outwardly; or laterally extending arms I32 having at theirgoutergf ends' .bearings 33j withinl which` the qpposite-.ends-oi aE Lrod or bar 34V are' lo cated and within which. they are'secured by bndingzscrew-S 35.; The upper end of a connecting-rod e36-gis" looseliy'connccted wfithrtherod or bar 34. At'itsopposite lower end. the connecting rod V36 isconnected to a crank pin 37, carriedupon the rotatable wheel 3S.4 The: wheel 38' is mounted upon ashaft 40su-p-A ported in bearings provided in the upper ends roi-the: posts 3'. The 'shaft-isl driven by power applied through abelt-41 to a wheel 42 mounted upon the saidshaft. The source of power for driving the belts' 15'. and 41 has:

not bcenshown but any suitable power forf that purpose may be employed.

' It maybe noted thatthe shafts 8 and 4()A are driven at diderent speeds. The shaft 8 may be driven at a speed of approximately ten revolutions per minute, while theshaft 40 may be driven at a speed of approximately fifty revolutions .per minute, but the revolutions'of. these shafts maybe adjustedjto such l' speeds asin practice: may be found to be most desirable and by which the most efficient results may be obtained.

It will be noted that the plates 22 are located in planes which are radial with respect to the axis of the shaft 8 and of the drum 12 mounted on said shaft. As pointed out previously, the surfaces of the tapered sides of the projections 5 are not radial with respect to the airisv of the said shaft. It follows from this relationship between the plates 22 and the cooperating surfaces of the projections 5' that when a plate 22 moves into position such that its outer or lower edge contacts with la side cf anyone of the projections 5 it makes an acute angle there with as indicated by thev dotted -lines at 43. The. movement of the plates 22 toward theI projections 5 not only operates .-to crush and disintegrate the lumps or 'clots which may be presentin the stock but also tends to cause a flowing movement of the stock toward the rotating drum 12. Such movement' tends to cause the passage of the stock through the elongated narrow perforations or slots therein. These slots are'very narrow andprevent the passage into the' drum and thence to the paper machine of fibres' which are of larger size than should be permitted to enter into the formation of the paper sheets.v

As previously described, the stock enters the trough or tank '4 through the port 20 and in order that it may pass intothe compartments on the opposite side of the projections 5 adjoining 'the said port the upper edges of said projections are located or spaced a substantial distance, say about one inch, from the drum 12. The upper or top edges ofthe outermost of the projections 5 are located nearer to the drum 12 than are .the edges of the two inner! of said projections. The space between the vupper edges 'of the outermost projections and the drum may, for example, be approximately one-quarter of an inch. This is for the purpose of permitting the stock to flow from the two outermost compartments provided b the projections 5 into the spacesindicated7 at 44 above the upper sides of the blocks 45 which are mounted in the angles between the outer sides ofthe outside projections 5 and the adjoining portion of the wall or body of the trough or tank 4.' In other words, some portion of the stock may iow back and forth between the spaces 44 and the two outside compartments formed by the projections 5.

In the operation of the device the rotation of the crank pin 37 with the wheel 38 causes reciprocatory movement of the connecting rod 36 to effect an oscillatory movement of the frame comprising the two couples of bars, each couple comprising bars 24 and 26, which frame constitutes a support for the agitating blades or plates 22. The distance of the crank pin 37 from its axis of rotation is such that the distance through which the frame comprising the couples of bars 24 and 26 is moved is not greater than will be permitted by the trough 4.

In order to facilitate the oscillatory movements of the frame, supporting rollers 46 are provided upon. the upright 'posts or standards 2 upon which the outermost of the curved bars 26 of each couple of bars forming a part of the frame structure are supported. As the frame is oscillated as previously described the rollers 46 rotate upon the supports therefor so that the oscillatory movements of the frame are facilitated or are more easily effected.

The stock Awhich enters through the port 20 into the tank 4 passes from the latter into the hollow rotary screen 12 and flows out through the opposite ends of the lower portions of the latter into the hollow projecting portions 6 and escapes from the latter through the outlet ports 47, and by means of pipes. (not shown) having connection with the said ports is conducted to its destination. It will be seen that by my invention I have provided a '-novel' construction of screen of the rotary type which while extremely simple is of 'a character such as to render it highly efficient in operation.-

Although I have described in detail the mechanismof the apparatus embodying the invention it will be understood that' the invention may. be embodied in amachine of different construction provided only that it shall operate in accordance with the principle of my invention'asjdisclosedhereini Furthermore2 the .f'm'achine -or 'apparatus embodying myv invention "may beemployed for the treating or handling' of any other materialsix'n'ilajto'pulpl-or which`1t"may"be or ma be' found to-beada'agpted.

aving thus described 'my invention, what I claim and desire to secure by'Letters Patentis; 1..A screening apparatus 'comprisingin combination a tank 'having projections therein which extend lengthwise' thereof and which project inwardly, the 'said projections being spaced from each' other to form compartments, -agit'ating meanslocated within the said compartments, and means for causing oscillatory movements of the said agitating means inthe said' compartments back-and forth between the said projections.

2. A screening apparatus of the character described, comprising in combination an open topped trough-shaped tank having projections therein which extend lengthwise thereof, the said projections being spaced from each other to provide intervening compartments, plates located within the said compartments, the said plates being located in planes which are radial with respect to th;-l axis of the'said tank, means for supporting the opposite ends of said plates, and means 'if for causing oscillatory movements of the said supporting means to cause back and forth movements of the said plates between the said projections.

3. A screening apparatus comprising in combination an open topped tank of trough shape, said tank having projections upon its inner side which extend lengthwise thereof, said projections being tapered, the surfaces of said projections extending in directions forming angles with planes which are radial with respect to the axis of the said tank, agitating plates located inthe said tank bctween the said projections, the said plates occupying planes which extend radially of the iii) axis@I ofthesaid:tank,'lmeans iforzfsupportng saidl platcs,.=fand-means for causing iosci-llae: tory movement of the said supporting means toeii'ect-back andortl-i move-ment of the smid' p1ates=betmenxadjcin1ing prosjlectim'ls v' 4i 'Inafscree stnlctui'egof' rotarysftype the combination of a rotatable screen, a tank. of trough-shapet having an 5 openxftopwhich the said screen lis' mounted,:the1saidl screen being spaced from 'the Iinner sid-@ict said-tank,l projections Alocated in the said tank and; extending lengthwise thereof, -the said projections being of inwardly. tapered shape in cross section and beingspad iroxneach V other, agitating-platesextending lengthwise off'tlre saidta'nlc and bein locatedrespectively in' thefspac'es 'between a joining projections; the saidplates being located in planesradial of the axis of the 'saidl rotatable screen, a sup:-` port. orthe saidrplms-,fand means for causoscillatory movements zo the said sup'- port :tm -eiectoscillatory flnovements; off-the said 'platesgbetween adjoining projectigns, the

Said plates `when mowed [into l fj uxtafposition; with respectto'thesurfacesot adioiningzpro-ir j ections forminglaut, angles therewith, -theg openings fof saidfang-lesextending inwardly towardthesaidrotatablescreen. i y-f 5. In a screen structure of rotary type, the combination of a rotatable screen, atankof trough shape .and of open top Within which the' said screen is' located, projections 4mounted upon the inner side of the saidtank which extend lengthwise of the said tank and which are spaced` fromeach other, the side surfaces of the said projections being located inplanes which are angularly-related .to planes-radialto the' axis of rotation ofthe saidscreen, agitating plateslocated the spacesbetwcen the said projections, said plates-beinglocated in planesradial with' respect to the axis of said screen, a supporting means for thev said plates, and meansfor causing movements of said supportingrneans to cause eachof the plates to oscillate in the space in which it is located between the opposing sides of adjoining projections.

6. In a screen of rotary type for treating pulp and like substances, the combination of a rotatable screen, a tank of trough-shape in which the said screen is located, projections mounted upon the inner side of the said tank and extending lengthwise thereof, the said projections being spaced from each other to form compartments extending lengthwise of the said tank, the inner edges of the intermediate projections being located greater' distances from said rotatable screen than are the inner edges of the outermost of said projections, and means for agitating the material Within the said tank, the said agitating means being located in the spa-ces between adjoining projections.

7 In a screen structure of rotary type the d5 combination of a rotatable screen, a tank of trough-shape ---Within;.whch1 theA said screen' is located, agitatingz means located -lrietweenl the said screen and-thesaid tank, and means located outside of saidscreen andlwithin saith tank with which Ithesaid agitatingmeans co` acts-to exert-a squeezing action upon portions meansJ located .f between-I the saidtank aand',

screen,f.-and :means'lecated 'between said-f tank; and.I screen with whiclfsaidb agtating "meansA coacts to exert' a squeezing action on themateiaflin said'tankiandfon the same through if'ifi'. Lv-i; 'vi'zr l: l' A." IInzas'oreefn :structure-of ,rotary type the comhilnationvof-af screen, a' 'tank of troughshape withznwhich the saidscreen iis located, thefinnerside-o-the said tank being* spacedV from the.- saidliscree, avfra-Ine the opposite ends '.orf which comprise. respectively twot cnrvedbars loneo .fwhichis located on the innerfside off the said tanl'r andthe other of:l which is 'located upon the. outer side thereof, means for securing the opposite ends of the bars-5.0i" each-couple ofbars-together, means. for-v connecting` and uniting-1 the said two couples of bars together, plates supported at their opposite ends upon the inner bars of the saidcouples` and .being located between the said screen and the said tank, and means for causing 'oscillatory movement ci the said frame to eiect oscillatory movements of the; said plates. to agitate the material in the tank underneath the said screen.

` 11. In a screen structure of rotary typethe combination of a4 rotatable screen, a tank of trough-shape Within which the said screen is located, a frame comprising two couples of curved bars one of which couples is located in adjoinin'grelation to one end of the said tank and the other couple in adjoining relation to the other end thereof, one'bar of each couple being located en the inner side of and in spaccdrelation to the said tank and the other bar oi' each couple being located on the outsideof and in spaced relation to the. saidtank, means for connecting and uni-ting the two conpies of bars. rotatablev means upon which the outside bar of each couple .of vbars is supported, plates mounted at their opposite ends upon the inner of the bars of the said couples of bars, said plates being located between .the

said tank and the said screen and in planes extending radially of the axis of said screen, and means for causing oscillatory movements of the said frame to effect corresponding movements of the said plates.

12. In a screen structure of rotaryT type the combination of a rotary screen, a tank in which the said screen is located, oscillating means located between said tank and screen for agitating material in its passage through the said screen structure, the said means including a plurality of members in spaced relation to each other, and spaced devices located between the said tank and screen with which the said members coact.

13. In a screen structure of rotary type for the treatment of pulp or other like material the combination of a rotary screen, a tank within which the said screen is located, the said screen being spaced from said tank, and means located between the said screen and tank for acting upon the said pulp or other material in its passage through the said screen structure, the said means including relatively movable members which coact with each other to exert a squeezing action upon the material in said tank and force the same through said screen.

In testimony that I claim the foregoing as my invention, I have hereunto signed my name this 15th day of April, A. D., 1930.

THOMAS OCONNOR. 

